scholarly journals Designing laser beams carrying OAM for a high-performance underwater communication system

2020 ◽  
Vol 37 (5) ◽  
pp. 876 ◽  
Author(s):  
Svetlana Avramov-Zamurovic ◽  
Abbie T. Watnik ◽  
James R. Lindle ◽  
K. Peter Judd
Keyword(s):  
Communication System ◽  
High Performance ◽  
Laser Beams ◽  
Underwater Communication

scholarly journals An OFDM Receiver with Frequency Domain Diversity Combined Impulsive Noise Canceller for Underwater Network

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Rie Saotome ◽  
Tran Minh Hai ◽  
Yasuto Matsuda ◽  
Taisaku Suzuki ◽  
Tomohisa Wada
Keyword(s):  
Frequency Domain ◽  
Communication System ◽  
Information Exchange ◽  
Communication Systems ◽  
High Performance ◽  
Autonomous Underwater Vehicle ◽  
Impulsive Noise ◽  
Distribution Data ◽  
Underwater Communication ◽  
Communication Performance

In order to explore marine natural resources using remote robotic sensor or to enable rapid information exchange between ROV (remotely operated vehicles), AUV (autonomous underwater vehicle), divers, and ships, ultrasonic underwater communication systems are used. However, if the communication system is applied to rich living creature marine environment such as shallow sea, it suffers from generated Impulsive Noise so-called Shrimp Noise, which is randomly generated in time domain and seriously degrades communication performance in underwater acoustic network. With the purpose of supporting high performance underwater communication, a robust digital communication method for Impulsive Noise environments is necessary. In this paper, we propose OFDM ultrasonic communication system with diversity receiver. The main feature of the receiver is a newly proposed Frequency Domain Diversity Combined Impulsive Noise Canceller. The OFDM receiver utilizes 20–28 KHz ultrasonic channel and subcarrier spacing of 46.875 Hz (MODE3) and 93.750 Hz (MODE2) OFDM modulations. In addition, the paper shows Impulsive Noise distribution data measured at a fishing port in Okinawa and at a barge in Shizuoka prefectures and then proposed diversity OFDM transceivers architecture and experimental results are described. By the proposed Impulsive Noise Canceller, frame bit error rate has been decreased by 20–30%.

scholarly journals The investigation of the features optical vortices focusing by ring gratings with the variable height using high-performance computer systems

2021 ◽  
Vol 2086 (1) ◽  
pp. 012166
Author(s):  
D A Savelyev
Keyword(s):  
High Performance ◽  
Focal Spot ◽  
Fdtd Method ◽  
Spot Size ◽  
Laser Beams ◽  
Optical Vortices ◽  
Focal Spot Size ◽  
Near Zone ◽  
High Performance Computer ◽  
Difference Time

Abstract The diffraction of vortex laser beams with circular polarization by ring gratings with the variable height was investigated in this paper. Modelling of near zone diffraction is numerically investigated by the finite difference time domain (FDTD) method. The changes in the length size of the light needle and focal spot size are shown depending on the type of the ring grating.

Efficient Space-Time Two Dimensional RAKE Receiver in Asynchronous Cooperative Communications Systems with Full Diversity

2014 ◽  
Vol 536-537 ◽  
pp. 719-725
Author(s):  
Dong Wu Li ◽  
Chang Xing Pei ◽  
Yun Liang Meng
Keyword(s):  
Cooperative Communication ◽  
Communication System ◽  
Cooperative Communications ◽  
High Performance ◽  
Rake Receiver ◽  
Space Time ◽  
Two Dimensional ◽  
Combination Rules ◽  
Performance Space ◽  
Full Diversity

A high-performance space-time two dimensional RAKE receiving algorithm was proposed in asynchronous cooperative communication system. the transmitting signals were estimated coarsely by traditional space-time rake receiver, then on the basis of that we introduce feedback technology, each multipath signal of transmitted signals was composed by the decision results, and then every multipath component in the received signal can be obtained by eliminating the composed multipath signals from the received signal. Finally, the multipath components were combined by space-time combination and multipath combination rules accordingly, so spatial as well as multipath diversities were achieved. Simulation results show that the new scheme can reduce the bit error rate dramatically compare with traditional space-time RAKE in asynchronous cooperative communication system.

Selection Relay-Based RF-VLC Underwater Communication System

2021 ◽  
pp. 177-192
Author(s):  
Mohammad Furqan Ali ◽  
Tharindu D. Ponnimbaduge Perera ◽  
Vladislav S. Sergeevich ◽  
Sheikh Arbid Irfan ◽  
Unzhakova Ekaterina Viktorovna ◽  
...  
Keyword(s):  
Communication System ◽  
Underwater Communication

High performance MoO3−x/Si heterojunction photodetectors with nanoporous pyramid Si arrays for visible light communication application

2019 ◽  
Vol 7 (4) ◽  
pp. 917-925 ◽  
Author(s):  
Yujin Liu ◽  
Guobiao Cen ◽  
Gai Wang ◽  
Junwei Huang ◽  
Suhang Zhou ◽  
...  
Keyword(s):  
Visible Light ◽  
Communication System ◽  
High Performance ◽  
Visible Light Communication ◽  
Fast Response ◽  
Optical Signal ◽  
Self Powered

Self-powered, fast-response heterojunction photodetectors based on nanoporous pyramid Si arrays are successfully developed. The photodetector is further integrated into a visible light communication system as an optical signal receiver.

Sign in / Sign up

Export Citation Format

Share Document